31. Tan 15° + Tan 30° + Tan 15° Tan 30º = ?

The expression equals 1 (one)

Step-by-step explanation:

Recall that all these trigonometric values have exact expression in forms of square roots.

There is also a very important rule for the tangent of an addition of angles, which states:

We can use this with

since tan of 15 degrees plus 30 degrees is tangent of 45 degrees, which we know is exactly 1 (one), we can multiply both sides of the equal sign by the denominator on the right, and then solve for exactly the expression we want to find:

So the answer we are looking for is 1 (one)

17 1/3

step-by-step explanation:

answer: it's d

step-by-step explanation: